Metastatic lesions in the leg below the knee are rare, and a metastasis to the patella is even more unusual. The following 4 patients were seen at Barnes Hospital between 1961 and 1968. One case is reported in detail to demonstrate the roentgenographic procedures which may be of help in arriving at a diagnosis. Case Reports Case I: A 52-year-old Negro male was admitted to another hospital in September 1967 with a three-week history of dysphagia and a 25-lb. weight loss. Physical examination was normal. A barium swallow and esophagoscopy with biopsy showed an epidermoid carcinoma involving the distal one-third of the esophagus. Thoracotomy revealed a widespread inoperable lesion involving the distal two thirds of the esophagus and the adjacent nodes. Radiation therapy was administered and the patient improved. In January 1968, immobilizing pain and swelling in the left knee developed. Upon the patient's admission to Barnes Hospital, the knee was swollen, hot, and tender. Motion was limited to 90° of flexio...